That assessment doesn’t mean I think Trump is the favorite for the Iowa caucuses or the GOP nomination, but it does reflect a fundamental shift in my thinking. I have believed and been arguing that once Iowa Republicans start to see the caucuses as an opportunity to select the next president, rather than an opportunity to express their frustration and anger, they will turn away from Trump (and other outsiders) and toward politically experienced, mainstream contenders.

After combing through the most recent surveys from the Iowa caucuses and talking with veteran Republican strategists, I can no longer say that with any certainty, though it remains the single most likely outcome.

Trump’s positioning improved in other ways, as well. In May, a clear majority of likely Iowa Republican caucus-goers — 58 percent — said they could never support him. That number fell to 29 percent in the most recent Selzer poll.

Remarkably, more likely caucus attendees said they could never vote for Kentucky Sen. Rand Paul (43 percent), New Jersey Gov. Chris Christie (48 percent), Ohio Gov. John R. Kasich (40 percent), former Florida Gov. Jeb Bush (39 percent), former Texas Gov. Rick Perry (35 percent) and former Pennsylvania Sen. Rick Santorum (35 percent) than said they could never support Trump for president.

Trump’s image in Iowa has improved at the same time his flaws, shortcomings and liabilities have become more apparent. For now, however, many voters just don’t seem to care. The Trump persona is compelling.

A friend of mine who has spent many years in politics recently emailed me from a Florida airport after sitting next to two women who were lifelong Democrats but intended to vote for Trump.

“They think someone needs to fundamentally change the political culture. They believe his policies are less important than his no-bullshit posture. Amazing,” he wrote.

Veteran Republican strategists involved in the GOP race (and working for other candidates) now tell me they believe Trump is in the race for the long haul and can and will win delegates, starting in Iowa, given that contests before March 15 are required to award delegates on the basis of proportional representation.

Trump’s early strength among the party’s most conservative and frustrated voters could help him amass a substantial number of delegates in the South (which has many early March contests).

So, I can no longer simply dismiss Trump (and the other “non-politicians”) as evidence of a Republican temper tantrum that will automatically fade into oblivion. Indeed, GOP insiders are worrying that Trump could well earn himself a speaking slot at the party’s convention, adding to the party’s general election challenges.

And if Trump falters, it is no longer clear who will benefit from the opening — Carly Fiorina, who excels at debating and taking on Hillary Rodham Clinton, or Ben Carson, a true outsider with a low-key style, Florida Sen. Marco Rubio, everyone’s seemingly second choice, or Jeb Bush, the man with the resources and stature?

There are so many odd things going on in the GOP race that my longtime colleague Norman Ornstein may be right that “the old rules no longer apply” and historical precedents are not of great use in understanding today’s Republican Party.

A few more thoughts about the Iowa outlook:

John McCain and Mitt Romney each drew about a quarter of the vote in Iowa the year they won their party’s presidential nomination. Those results fit nicely with the fact that 22 percent of respondents in last month’s Des Moines Register/Bloomberg survey described themselves as a “business-oriented establishment Republican.”

And yet, Bush was the first choice of only 6 percent of Iowa Republican caucus-goers in that poll, while Christie (2 percent) and Kasich (2 percent) picked up a few more scraps. Rubio (6 percent) could be getting some of that constituency, as could former HP CEO Fiorina (5 percent), but Bush’s slow start with that chunk of the party is noteworthy.

Of course, Bush’s allies have $100 million to spend on the race, and his supporters will begin television advertising shortly to boost his standing, both by pointing to his conservative record and to his opponents’ flaws. It’s obviously too soon to write him off. But it’s also worth noting that the former Florida governor has a lot of work to do and a lot of resistance to overcome in his own party.

Paul’s performance in the race has been stunningly unimpressive, leading to increased chatter that he will leave the presidential contest sooner rather than later to focus on his run for re-election. Former Rep. Ron Paul won 21 percent of caucus-goers according to the 2012 entrance poll, yet his son drew only 4 percent in the August Selzer & Company survey.

Have libertarians abandoned the son because he has been more of a team player than his father ever was? Or are they simply waiting to get behind him, as they did with his father? Remember, Ron Paul drew only 7 percent in a June 2011 Des Moines Register poll and 13 percent in a late October Register poll when the caucuses took place on Jan. 3, 2012.

Scott Walker has slipped badly in ballot tests (down from 17 percent in May to 8 percent in August), a fact not unnoticed by the national media. But his favorable rating among likely caucus attendees, 71 percent, is second only to Carson’s 79 percent favorable rating, and only 16 percent of likely caucus attendees say they could never support him for president.

We will see whether the new TV ad from Walker’s Super PAC boosts his standing and whether the Wisconsin governor reverts back to his early form, when he impressed observers.

Ted Cruz clearly has sidled up to Trump in an effort to inherit the businessman’s support when he collapses. But if Trump doesn’t collapse, it’s difficult to see Cruz having a path.

This GOP race is so unpredictable because so much has changed and the dynamic of the crowded contest may well encourage hopefuls to stay in the race longer than they normally would.

Voters have been angry for years now, but many Republicans seem fed up and willing to think the unthinkable. Super PACs allow candidates who can’t raise cash from the grass roots to hang on, and Trump’s early success encourages other candidates to stay in the race, figuring that he will fade and create a new opportunity for others.

Trump’s flamboyant behavior, boastfulness and outlandish, undiplomatic comments could derail his campaign at any time. And it is still possible that as the caucuses approach, Republican voters will evaluate the candidates more on the basis of experience and thoughtfulness than on how frustrated they are and how much they can shake up the status quo.

But Trump is proving to be a successful demagogue who understands how to manipulate the media and voters’ feelings of anger. And that makes the Republican race more unpredictable than ever.